Rev. Al Sharpton called for national policing legislation akin to the Civil Rights Act Wednesday at the kickoff his National Action Network’s annual convention, just after the arrest of a white South Carolina police officer for murder in the shooting of an unarmed black man.

“There must be national policy and national law on policing,” Mr. Sharpton said. “We can’t go from state to state, we’ve got to have national law to protect people against these continued questions.”

The convention kickoff came just hours after it was announced that a North Charleston, S.C., police officer would be charged with murder in the death of Walter Scott—who can be seen in a widely publicized video running away from the officer, while the officer shoots into the man’s back repeatedly. The video offers a markedly different story than the one the officer first offered up: that Scott had stolen his taser and left him in fear for his life.

Mr. Sharpton praised the city’s mayor and police chief for bringing the charges, but said the nation couldn’t rely on the judgement of local officials, the New York Observer reports.

“We commend them, but we cannot have a justice system that hopes we have a mayor in the right city or a police chief,” he said. “We have to have one policy that is national.”